Refrigeration Basics

Modern refrigeration has many applications. The first, and probably the most important, is the preservation of food. Most foods kept at room temperature spoil rapidly. If kept cold, they keep much longer.

Before looking at the operation of mechanical refrigeration, it is important to understand the physical and thermal properties of the mechanisms and substances used to extract heat. Removing heat from the inside of the walk-in is somewhat like removing water from a leaking boat. A sponge may be used to soak up the water. The sponge is held over the side, squeezed, and the water released overboard. The operation may be repeated as often as necessary to transfer the water from the boat into the lake.

In a walk-in, heat instead of water is transferred. Inside the walk-in heat is absorbed, "soaked up", by the liquid refrigerant in the evaporator. This happens as the refrigerant changes from a liquid to a vapor. After the refrigerant has absorbed heat and turned it into a vapor, it is pumped into the condensing unit located outside the refrigerated space. Here it is compressed. The heat is "squeezed" out by high temperature. Then it is cooled in the condenser. This cycle repeats until the desired temperature is obtained.

Cold is a relative term used to describe low temperature. Cold is not something that is produced. Rather, heat is removed and the resulting condition is cold. A refrigerator produces a condition called "cold" by removing heat from inside the refrigerator and the stored content. You have probably felt the heat on the floor as you walked by your refrigerator in your home. The principle of heat removal is the same for your walk-in cooler and/or freezer. If your looking for a food warmer or a conventional oven , feel free to check out Thermodyne .

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